Below are the detailed explanation of all stages and why it is crucial for the system.
1st Stage: Pre-Filtration
Although the semi-permeable membranes are capable of filtering the vast majority of water-borne contaminants, they can get clogged up easily with larger particles.
Sending the unfiltered water directly through the membrane will essentially shorten its lifespan.
A pre-filter usually consists of carbon and sediment filters which are responsible for removing the largest particles in the water in preparation for the membrane to remove whatever remains in the water.
You can make things even easier on the system by installing some kind of water softener at home.
2nd Stage: RO Membrane Filtration
With the larger particles filtered out, the water can now be pushed through the membrane with the aid of water pressure.
The membrane gets rid of microscopic contaminants such as lead, arsenic, and dissolved solids, thus making the water suitable for human consumption.
3rd Stage: Storage
The multi-stage filtration process will take a while to generate clean water. Hence, most of the system will funnel the filtered water directly into the storage tank. The storage tank ranges in size between 3.2 to 4 gallons.
4th Stage: Post-Filtration
In the unlikely event whereby contaminants pass through the membrane, a carbon filter will act as a final protective layer that removes any remaining contaminants before the water is directed out via the faucet.
Old tubes and storage tanks sometimes contribute to bad odors and foul tastes of the filtered water. This is where the post-carbon filter comes in and removes it leaving behind only clean water.